The present invention relates to an apparatus for performing either a detection or an examination of an object by way of ultrasonic waves, and more particularly to a phase adjustment apparatus for phasing signals received from a plurality of ultrasonic transducer elements.
Ultrasonic apparatuses in which delays are applied to reception signals of ultrasonic waves detected by a plurality of arrayed transducer elements, wave fronts of the ultrasonic waves derived from a desirable azimuth, or a desirable distance are set to be the same phases, and these ultrasonic waves signals are summed with each other to obtain improved azimuth resolution, have been widely utilized in various technical fields such as a flaw examination for an object, and sonar or ultrasonic imaging of a biological body.
In JP-A-52-20857 (1977) and U.S. Pat. No. 4,140,022, there have been described such apparatuses that the reception signals are frequency-shifted into the low frequency signals by mixing the respective reception signals with the reference signals, the phases of which have been controlled, and thereafter the delays are applied to the low frequency signals so as to be summed with each other. In these apparatuses, it may be understood that the frequency-shift phasing methods are performed.